1. Field of the Invention
This invention relates to portable computers and in particular to apparatus and methods for mounting and electrically connecting an expansion card to a portable computer.
2. Description of the Prior Art
Expansion cards are often used to add to or expand the capabilities of a computer. An expansion card includes a separate printed circuit board combining appropriate circuitry for performing the added or expanded functions. The expansion card will typically further include a physical connector for interconnection to the electrical bus system of the computer via expansion slots on the mother board of the computer configured to receive the connector of the expansion card so as to provide a physical and electrical interconnection between the expansion card and the mother board of the computer. The terminology "mother board" is used to refer to the printed circuit board containing the microprocessor and associated circuitry of the computer. Expansion cards are typically used for additional memory, input-output, interconnection to network or modem, providing graphics capability, simulating a mainframe terminal or other functions. The bus system will include one or more electrical connectors used as a path over which information or power is transmitted between different locations throughout the computer.
The most common expansion card standard in the personal computer industry is the IBM PC compatible expansion card whose pin assignments are defined in IBM Technical Reference 6361459. Expansion cards will have a varying length with a full length expansion card typically having a length of roughly 34 cm. Because of limited space often available and because the full length is not required by the expansion card's circuitry, many expansion cards are sold as 1/2 full length of 2/3 full length. However, even these reduced length expansion cards will typically not fit in a portable or laptop computer. This necessitates the expansion card being left outside the portable computer's casing when in use. This is highly undesirable as the expansion card is exposed to dirt and other particles and can be easily damaged. Moreover, this arrangement reduces the computer's portability, since the expansion card typically must be disconnected prior to transport and separately packaged. There have been some attempts at developing separate expansion card housings for enclosing the expansion cards. These housing might be physically detached from the portable computer and have a suitable electrical cable interconnecting the expansion cards contained therein to the expansion slots of the portable computer. Other expansion card housings are physically attached to the portable computer. However, both arrangements detract from the portability of the computer since the either adds significantly to the size of the portable computer and/or must be disconnected and separately packaged for transport.
Additionally, the interface protocol of a portable or laptop computer is often different from that of a standard IBM compatible expansion card. Accordingly, the interface signals must be converted from one interface protocol to another.
The present invention solves these and other problems associated with the prior art.